1,721,430 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The Reorganization of Rainband after Typhoon Moved Over the Central Mountain Range of Taiwan
No full text部分颱風西行侵襲台灣通過中央山脈後，其對流雨帶有重新組織發展的現象；例如凡那比颱風（Fanapi，2010）西行侵襲台灣期間，當其中心通過中央山脈後，在台灣海峽南部有一東西走向雨帶重新組織發展，造成高雄地區劇烈降雨和淹水。本研究使用中央氣象局歷史颱風資料之雷達回波合成圖（CV），計算颱風內核區強回波像素比例之變化，選取西行經中央山脈後有內核雨帶重建之個案，分析其重要特徵；並使用中尺度模式WRF模擬凡那比颱風侵台期間之雨帶重建事件，探討對流之演變及導致雨帶重建的原因。分析時亦選取西行過山但未發生內核雨帶重建之颱風個案，並與有發生雨帶重建之颱風進行比對分析。結果顯示，過山之後有雨帶重建之颱風，於侵台期間其環境有較強的850 hPa西南風分量，以及較強的深層（200?850 hPa）垂直風切之現象，而重建個案向西的移速分量亦較沒有重建之個案緩慢。
利用WRF模式模擬結果顯示，凡那比颱風雨帶重建前，台灣海峽北部潮濕、南部中層則較乾燥。雨帶重建期間，強輻合帶由屏東山區開始發展，並逐漸向西延伸至高雄外海，高相當位溫之空氣從近海面藉由颱風環流風場進入台灣海峽，並與源自華南地區中層沉降之低相當位溫的空氣於海峽南部會合，而造成顯著的相當位溫梯度，飽和空氣於相當位溫梯度大之區域舉升，並因環境具較強的垂直風切，產生類似颮線系統之結構。雨帶對流發展期間，沿雨帶軸線方向之低層噴流，以及因雨滴蒸發冷卻而產生的冷池，皆為可能有利雨帶對流的發展及維持之結構
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
From Rotaxane toward Molecular Machine
No full text我們成功地開發出一種可受pH值控制的分子開關(molecular switch)系統－[2]車輪烷與具TTF側臂分子夾錯合體。在不同pH值的條件下，藉由TTF與[2]車輪烷之間電荷轉移吸收改變所造成的顏色變化，使一般人可憑肉眼觀察顏色來判別其操作狀態。此分子開關系統在溶液中呈現深綠色，加入鹼(三乙基胺)後顏色迅速轉為黃色，稍後加入酸(三氟醋酸)又會再變回深綠色。Herein, we used a complex made up of a pH-controllable molecular switch and a molecular clip with TTF side walls. The molecular switch consisted of a [2]rotaxane with a dumbbell component that had dibenzylammonium and 4,4'-bipyridinium "stations" that were able to "lock up" the ring-shaped component known as a macrocycle. Under basic conditions the macrocyle moved to the bipyridinium station, displacing the molecular clip and dissociating the switch/clip complex. The sequential addition of a base and an acid induces migration of the macrocyclic unit of this [2]rotaxane from the NH2+ station to the bipyridinium unit and back again. In turn this controls the availability of the bipyridinium station for complexation with the molecular clip and results in significant colour changes that are clearly visible to the naked eye.目錄
摘要……………………………………………………………………Ⅲ
論文發表………………………………………………………………Ⅴ
目錄……………………………………………………………………Ⅵ
流程……………………………………………………………………Ⅶ
圖表……………………………………………………………………Ⅷ
壹、緒論……………………………………………………………1
1.1 前言…………………………………………………………1
1.2 內鎖型分子：車輪烷及連環體……………………………2
1.3 超分子系統…………………………………………………6
貳、結果與討論……………………………………………………12
2.1 可由顏色判斷狀態的分子開關……………………………12
2.2 以2,2'-雙吡啶陽離為辨識站的分子開關及分子梭
之合成與研究………………………………………………………25
參、實驗部分………………………………………………………36
肆、參考文獻………………………………………………………49
附錄…………………………………………………………………5
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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